operational

* COMMENT -*- mode: org -*-
#+Date: 2015-09-08
Time-stamp: <2015-09-08>
#+STARTUP: content
* later								      :entry:
* current							      :entry:
** 
** 2015-09-08 support reading input from stdin
* done								      :entry:
** DONE 2015-09-08 it doens't handle parse failures.
Should warn about lines that failed to parse, ignore that line and continue
parse the rest.

Return value should be changed to failed lines [ByteString] and successfully
parsed lines [AccessLog]. Parser should have a alternative failure case.